Pearl Millet Seeds Research Articles

Relations génétiques entre les populations de mils sauvages et cultivés : résultats d'une enquête au Mali

Genetic relationships between wild and domestic populations of pearl millet : results from a survey in Mali. Pearl millet (Pennisetum typhoïdes) seeds were collected from Mali in november 1985. ORSTOM and IBPGR having already obtained exhaustive collections of various forms of pearl millet, the aim of this project was to collect a limited number of samples from areas where pearl millets of domestic, wild and intermediate types (chibras, hybrids between wild and domestic types) are found in a sympatric or allopatric situation. The three types coexist with non sexual barriers. The samples were collected in three areas : — Nioro du Sahel ; — Bandiagara ; — Gourma-Rahrous. Enquiries carried out within the local population led to the knowledge of the growing habits (cultivation, seed preparation, behaviour towards chibras or wild types) as well as the feeding habits and the usual names for the various types of pearl millet. This information gives a better view of the related evolution within wild and domestic populations of pearl millet in precise ecological conditions.

The influence of temperature during seed development on the germination characteristics of millet seeds

Abstract. The cardinal temperatures, rate of germination and final percentage germination of pearl millet seeds were measured for seeds raised in greenhouses maintained at mean air temperatures of 19, 22, 25, 28 and 31°C. The results showed that cardinal temperatures for germination are unaffected by the temperature during seed development and growth. However, the conditions during seed growth did affect seed size and, subsequently, germination rate and seed viability.

Time, Temperature and Germination of Pearl Millet (Pennisetum typhoidesS. & H.): III. INHIBITION OF GERMINATION BY SHORT EXPOSURE TO HIGH TEMPERATURE

Seeds of pearl millet were germinated on wet filter paper at temperatures up to 50 °C. In one experiment, the temperature was held at 50 °C during imbibition and was then lowered to 32 °C or 25 °C. Germination rate and the maximum fraction of seeds germinating (Gm) both decreased as the time of exposure to 50 °C increased. In contrast, exposure to 50 °C after imbibition for 8 h slowed germination but did not significantly reduce Gm. When the 'high' temperature imposed after imbibition was reduced from 50 °C to 45 °C, there was a small reduction in the rate of germination but not in Gm. The responses have implications for the optimum time of sowing in the tropics when maximum daytime soil temperature at the depth of sowing is in the range of 45-50 °C.

Drechslera setariae in Indian pearl millet seeds, its seed-borne nature, transmission and significance

Three of 5 samples of Pennisetum typhoides from Mysore showed 80-90% infection with D. [Cochliobolus] setariae and the other 2 showed 56 and 38%. The fungus was deep-seated and the embryos extensively infected. In inoculation tests the seedlings were very susceptible up to the age of 2 wk; symptoms included damping-off, leaf blight and leaf spots. Field observations in Mysore indicated that P. typhoides seeds and seedlings are damaged extensively by this pathogen during humid and cool weather (24 deg C av. day temp.). Surviving seedlings recovered as the season progressed and new growth was unaffected by the disease until just before heading, when leaf spots appeared. At maturity lesions increased rapidly and infected leaves showed blight from the tips downwards. Abundant brown spots appeared in the flag leaves, glumes and exposed surfaces of the grain. It is believed that this disease is prevalent but has been unnoticed hitherto because of the presence of other more conspicuous diseases

Time, Temperature and Germination of Pearl Millet (Pennisetum typhoidesS. & H.)

Seeds of pearl millet were germinated on wet filter paper at temperatures up to 50 °C. In one experiment, the temperature was held at 50 °C during imbibition and was then lowered to 32 °C or 25 °C. Germination rate and the maximum fraction of seeds germinating (Gm) both decreased as the time of exposure to 50 °C increased. In contrast, exposure to 50 °C after imbibition for 8 h slowed germination but did not significantly reduce Gm. When the 'high' temperature imposed after imbibition was reduced from 50 °C to 45 °C, there was a small reduction in the rate of germination but not in Gm. The responses have implications for the optimum time of sowing in the tropics when maximum daytime soil temperature at the depth of sowing is in the range of 45-50 °C.

Carpel infection and establishment of downy mildew mycelium in pearl millet seeds

The carpels of pearl millet (Pennisetum typhoides) are infected bySclerospora graminicola. Vegetative mycelium present in the diseased mother plant infects the carpel through the stalk of the spikelet. This process may or may not cause hypertrophy. Zoospores infect the carpel through the stimga and style, without inducing hypertrophy. Infection process leading to the establishment of downy mildew mycelium in the carpellary tissue and its implications are discussed.

Sclerospora graminicola in pearl millet seeds and its transmission

Sclerospora graminicola (Sacc.) Schroet. inoculum may be present in pearl millet seed either as oospores externally or in the form of dormant mycelium internally. Oospore inoculum was detected by using the washing method, and mycelial infection by the modified embryo count procedure. Fifty-nine seed samples out of ninety-three obtained from different sources were found contaminated with oospores whose viability was checked by the tetrazolium test. Percentage of viable spores ranged from 5.5 to 20.2. Forty-three samples showed mycelial infection of 0.1–7.5 Per cent in various parts of the seed. Seeds from healthy-looking plants are not necessarily pathogen-free. Transmission was obtained from a two-year-old seed sample contaminated with oospores and from mycelium. The significance of the results with particular reference to survival of inocula, development of epidemics and quarantine implications in international movement of germplasm are discussed.

Effects of Grain Development and Thermal History on Grain Maturation and Seed Vigour ofPennisetum americanum

Studies were made of the viability and vigour of seeds of pearl millet (Pennisetum americanum) harvested at different stages of grain development and from different controlled-temperature environments. Seed viability and vigour of the next generation were dependent on the extent of grain development at harvest. Where grain had developed for only one-third of the potential grain-filling period before harvest, seed viability and vigour were greatly reduced. Harvest at or after the middle of grain-filling did not reduce seed viability or vigour. The temperature at which the grains had developed did not affect seed viability, but grains that had developed at 21/16 °C (day/night) produced seedlings of greater height and dry weight than those from grains which had developed at higher temperatures

Gene Loss in Pearl Millet Germplasm Pools1

Six different germplasm pools of pear millet, Pennisetum americanum (L.) K. Schum. (formerly P. typhoides (Burm.) Stapf and Hubb) were advanced in isolation three to five generations. A comparison of the last generation with the first showed that advancing germplasm pools of this cross‐pollinated (up to 85%) species narrowed phenotypic variability, lost genes, and obscured hard to recover characters such as very long seed heads. A significant shift in maturity resulted from an attack of European corn borer. I believe, therefore, that longtime storage is the only practical way to preserve pearl millet germplasm without loss. At Tifton, pearl millet seeds dried to less than 12% moisture, enclosed in airtight containers, and stored at 5 C germinated well (70%) after 26 years. Growing germplasm pools in an environment with short days and temperatures approaching 40 C will make most genotypes flower at about the same time, facilitate intennating, and reduce gene loss. Pooling fewer lines, selecting plants to advance the population as if they were self‐pollinated, and preparing pools from equal numbers of live seeds from each selected plant will also help to reduce gene loss

Fatty Acid Composition of Oil from Pearl Millet Seed1

AbstractStudies of the fatty acid composition of oil from seed of pearl millet, Pennisetum typhoides (Burm.) Stapf and C. E. Hubb., have permitted comparisons of five extraction procedures, genetic diversity in 65 lines, seed‐size differences, and seed maturation in four inbred lines during two growing periods (early and late). Oil extracted with a nonpolar solvent was different in fatty acid composition compared with oil from extraction procedures using polar solvents. The range in fatty acid composition of 65 pearl millet lines of diverse origin was: 16.7 to 25.0% palmitic, 1.8 to 8.0%s stearic, 20.2 to 30.6%o oleic, 40.3 to 51.7% linoleic, and 2.3 to 5.8% linolenic acid. In one variety, the proportion of linolenic acid of total oil was found to consistently increase as seed size decreased.A study of oil composition in four inbred lines during seed maturation showed that the most rapid and greatest changes in fatty acid composition occurred during the first 16 days after anthesis. Changes in fatty acid composition were small beyond 24 days after anthesis. The relative amounts of palmitic and linolenic acids decreased during seed maturation, while stearic and linoleic acids increased. Proportion of oleic acid increased during early seed maturation and then decreased. Although large differences in fatty acid composition were found between the early and late season crops during early stages of seed development, the final fatty acid composition of the mature seed was similar for the two crops.

Breaking Dormancy in Seeds of Pearl Millet, Pennisetum typhoides1

Seeds of most pearl millet, Pennisetum typholdes (Burm.) Stapf and C.E. Hubb., genotypes are partially dormant for several weeks after harvest. Storage in airtight containers at 0 to 6 C extended the dormancy period in such seeds to more than 12 months. Leaching in running water and exposure to light failed to improve germination and exposure to dry heat from 60 to 90 C for 1 to 72 hours reduced the germination of dormant (but not nondormant) seeds. Soaks in water solutions of the following chemicals listed in order of decreasing effectiveness improved the germination of partially dormant pearl millet seed: 2‐chlorocthanol, hydrogen peroxide, sodium hypochlorite, potassium nitrate, sulfuric acid, potassium salt of gibberellic acid, and kinetin. A 1‐hour soak in a water solution of 1% 2‐chloroethanol plus 0.5% sodium hypochlorite increased the germination of dormant pearl millet seeds significantly more than any other chemical without reducing the germination of any genotype tested.